The present invention relates to a new and distinct variety of shiitake mushroom plant named ‘FFT-52’ which is characterized by a greater pileus diameter, a greater pileus thickness, a higher crop yield, an easier harvesting operation, and a higher resistance to a high-temperature load.
The claimed ‘FFT-52’ is a variety of shiitake mushroom produced by crossbreeding Japanese registered shiitake mushroom varieties ‘KB-2010’ (hereinafter referred to simply as ‘KB-2010’) (Registration No. 8118) and ‘JMS KV-92’ (hereinafter referred to simply as ‘KV-92’) (Registration No. 9781) and further crossbreeding the resulting variety ‘KBT-1809’ and another shiitake mushroom variety ‘KBT-304’ (see FIG. 1). More specifically, ‘FFT-52’ was produced through the following crossbreeding and cultivating process:                (1) In November 2006, dikaryotic mycelia produced by crossbreeding single-spore-derived monokaryotic mycelia of ‘KB-2010’ and ‘KV-92’ were allowed to grow into a colony, and a strain superior in mycelial growth and colony condition was selected from the colony.        (2) From December 2006 to July 2008, a cultivation test was performed by cultivating the selected strain in a fungal bed, and a strain superior in fruit body shape and crop yield was selected and named ‘KBT-1809’.        (3) In December 2010, dikaryotic mycelia produced by crossbreeding monokaryotic mycelia of ‘KBT-1809’ and ‘KBT-304 (stock strain)’ were allowed to grow into a colony, and a strain superior in mycelial growth and colony condition was selected from the colony.        (4) From February 2011 to December 2012, a cultivation test was performed by cultivating the selected strain in a fungal bed, and a strain superior in fruit body shape and crop yield was selected and named ‘FFT-52’ (inventive variety).        (5) From 2013 to 2014, an extensive cultivation test was performed. In 2014, it was confirmed that ‘FFT-52’ has stable characteristics.        
An asexually reproduced clone of the inventive variety is identical to the original inventive variety in all distinguishing characteristics.